Here is some information about chickenpox and smallpox. Basically smallpox is no longer around. Chickenpox however is.
Chickenpox is a common illness among kids, particularly those under age 12. An itchy rash of spots that look like blisters can appear all over the body and may be accompanied by flu-like symptoms. Symptoms usually go away without treatment, but because the infection is very contagious, an infected child should stay home and rest until the symptoms are gone.
Chickenpox is caused by the varicella-zoster virus (VZV). Kids can be protected from VZV by getting the chickenpox vaccine, usually between the ages of 12 to 15 months.
A person usually has only one episode of chickenpox, but VZV can lie dormant within the body and cause a different type of skin eruption later in life called shingles (or herpes zoster). Getting the chickenpox vaccine significantly lowers your child's chances of getting chickenpox, but he or she may still develop shingles later.
I had chickenpox when I was 7. I got it from my little brother and sister after they were better, while we were on vacation!! I also developed shingles when in my early 30's and that is not fun...lol very painful.
Smallpox is an infection caused by the variola virus. For centuries, epidemics of smallpox affected people all over the globe, and the disease was often serious. But in 1796, an English doctor named Edward Jenner discovered a way to protect people from getting smallpox, which led to the development of the first smallpox vaccine.
The vaccine worked so well that there hasn't been a case of smallpox in the United States since 1949. The United States stopped vaccinating the general population against smallpox in 1972 because the disease was no longer a threat.
The world's last known case of smallpox was reported in Africa in 1977. In 1980, the World Health Organization (WHO) announced that smallpox was wiped out — the first (and only) time in history that an infectious disease was declared eliminated from the planet.
Hope this helps,
Mari

Small pox I think is not existed anymore. From what I remember Edward Jenner discovered the vaccine for this. I had a chicken pox when I was a kid up to now the scar is noticeable. Chicken pox is dangerous to the pregnant women and no need to worry about it because there's a vaccine and you can't infected again once you had it.

Yes chicken pox and measles are the diseases usually found in children and young kids but as far as small pox is concerned it has been eradicated and the health department has fixed an amount if someone can report a case of small pox...I had chicken pox when I was young it was very awful...